Refrigerating apparatus



Dec. 15, 1931. G. F. WOELFEL REFRIGERATING APPARATUS Original Filed Jan. 10. 1929 aiiu Wz z Patented Dec. 15, 1931 PATENT OFFICE enonen r. woman, or mmrson', Emma, ASSIGNOR To run GOMMERCIAL CLEARING nromrrorr, or :rncxsomnn, momma, A CORPORATION or Fromm.

nnrnrenanr'rne APPTD'S Application filed j'anuary 10, 1929, Serial No. 331,677. Renewed February 20, 1931.

This invention relates to motor and compressor units for use in refrigerating apparatus, and more particularly to the production of a unit of this character which is free from packing glands.

An important and more specific object of the invention is the production of a unit of this character of such construction that the motor casing forms a seal for the only proj ecting operating element of the compressor,

so that the necessity for packing g ands is eliminated. k

A further and more specific object of the 1nvention is the production of a construction of the character just described, wherein the collection of oil within the motor casing, due to the natural tendency of the oil to creep along the rotating shaft and to the difierence in pressures,which is bound toresult in operation, is eflectually prevented from reaching prs sure to which the compressor is subjected.

hese and other objects I attain by the consgruction shown in the accompanying drawi g, wherein for the purpose of illustration is shown a preferred embodiment of my in vention and wherein The figure is a sectional view through a motor compressor unit constructed in accordance with my invention, the connections of matically indicated.

Referring now more particularly to the drawing, the compressor casing includes a cylinder 10, a valve chamber 11 and a base 12. The base 12 has opposed openings 13 for the reception of bearing elements 14 and 15. The bearlng element 14 has a closed outer end 16 and thus seals the opening 13 in which it is disposed. The bearing element 15 has an open outer end to permit projection therethrough of the shaft 17 which constitutes at 14 and 15 are arranged eccentrics 26 and 27 the unit to the system being semi-diagram-v tutes an outlet plate and has connected thereonce the drive shaft of the compressor and the armature shaft of a motor and to which the rotor 18 of the motor is secured. This bearing element, in addition to the attaching flange 19 which it employs in common with the bearing element 14, has an integral bell flange 20 sealing-at its outer edges to an airtight casing 21, which supports the stator 22- of the motor, the motor terminals being let through the walls of this casing in a manner perfecting the seal thereof, as generally designated at 23. From the upper portion of the bearing 15 and preferably in alignment with the oil cup 24 thereof, a small tube 25 is led through the flange l9 and then downwardly along the bell flange 20 and inserted into the casing 21 adjacent the bottom thereof, for a purpose presently to appear.

Between the adj acentends of the bearings and an intermediately disposed counterweight 28, which may be conveniently secured to the shaft as against rotation by a single key 29. These threeelements are in contacting relation with one another, so that they form, in effect, a solid unit, the ends of which abut adjacent ends of the bearings 14 and 15, so that no available space is provided, permitting any whipping action of the shaft between these hearings.

The eccentric 26 operates the pitman 30 of the compressor'piston 31 and the eccentric 27 the pitman 32 of the valve 33. The valve 33 is of the type described in my prior application for patent on refrigerating apparatus, filed March 1, 1928, Serial No; 258,279, and is maintained in engagement with its seat 34 by a follower 35 which is sealed to a plate 36 by a diaphragm 37. The plate 36-constito \an outlet pipe 38 leading to or forming one end of the usual condenser 39. As pressure is built up. in thecondenser, this dia hragm expands, forcing the valve more orcibly against its seat to increase the integrity of the seal provided thereby, as set forth in the application above identified.

The intake chamber 40 of the compressor, which is intermittently connected by this valve with the interior of the cylinder 10, is

connected by a conduit 41 with the low side 42 of the system, while the upper end of the valve chamber is likewise connected with this low side by a conduit 43. Since the lower end of the valve chamber is in direct communication with the base, it follows that any depression in the valve chamber will be extended to the base, so that there will be no interference with gravity return of oil from the low side 42 through a conduit 44 to the base 12. This return is controlled by a float valve 45 of any suitable construction. With a construction of the above character, it will be noted that the use of packing glands associated with moving parts of the compressor is entirely eliminated, and a perfect seal of the system thereby rendered possible, so that there will be no losses of the relatively high priced refrigerating fluids employed therein.

When in operation, depression of the low side will be extended to the valve chamber, the base and through the tube 25 to the interior of the motor casing. During this period, there will be a certain transfer of oil from the base 12 to the motor casing along the shaft 17. This oil will naturally collect in the bottom of this motor casing which acts as a sump therefor. When operation is checked and pressures in the casing balance, more oil will pass .to the motor casing along this path, for naturally the pressures will first balance in the compressor. When the compressor is again started, however, the reverse is true and depression will first occur in the compressor and in the valve chamber and base thereof. This depression unbalancing the pressures in the motor casing and compressor base will cause a transfer of air and gas from the motor casing to the compressor casing through the tube 25, and since the tube 25 will be submerged in any fluids contained in the motor casing, such fluids will be forced from the motor easing into the compressor casing.

It is pointed out that in addition to the advantages above set forth, a relatively long bearing may be provided for the shaft while, at the same time, the overall length of the unit represented by the motor and compressor is materially reduced, so that an extremely solid, compact and durable unit is produced.

It will be obvious that the construction hereinbefore set forth is capable of a certain range of change and modification without materially departing from the spirit of the invention and I accordingly do not limit myself to such specific structure except as hereinafter claimed.

I claim 1. In a motor compressor unit for refrigerating systems, a compressor casing including the usual cylinder base and valve chamher, the base having horizontally aligned bearings one of which has its outer end Open,

a shaft rotatable in said bearings, one end of the shaft projecting through the open outer end of said bearing, a motor casing surrounding said end of the shaft and operatively supported from and sealed to the compressor casing, a stator carried by the motor casing, a rotor for coaction with said stator carried by said end of the shaft, means for maintaining a constant oil level in the compressor casing base, means for creating a partial vacuum in said base when the compressor is in operation, and a connection between the lower portion of said motor casing and the compressor base above the level of oil therein.

2. In a motor compressor unit for refrigcrating systems, a compressor casing including the usual cylinder base and valve chamber, the base having horizontally aligned bearings one of which has its outer end open, a shaft rotatable in said bearings, one end of the shaft projecting through the open outer end of said bearing, a motor casing surrounding said end of the shaft and operatively supported from and sealed to the compressor casing, a stator carried by the motor casing, a rotor for coaction with said stator carried by said end of the shaft, means for maintaining a constant oil level in the compressor casing base, means for creating a partial vacuum in said base when the compressor. is in operation, and a tube having its lower end disposed within the motor casing and contiguous to the bottom thereof, the upper end of said tube extending to the interior of the compressor casing above the normal level of oil therein.

3. In a motor compressor unit for refrigerating systems, a compressor casing including the usual cylinder, base and valve chamber, the base having opposed openings, bearings having flanges secured and sealed to the edges of the openings, one of said bearings having its outer end open, the other bearing having its outer end closed, a piston in said cylinder, a valve in said chamber, operating connections between the shaft and said piston and valve, the first named bearing having a bell flange, an imperforate motor casing secured and sealed to said flange, a stator carried by said motor casing, a rotor'carried by the outer end of the shaft for coaction with said stator, means for maintaining a constant oil level in'the base, means for creating a partial vacuum in the base when the compressor is in operation, and a connection between the lower portion of said motor casing and the base above the level of oil therein.

4. In a motor compressor unit for refrigerating systems, a compressor and hollow base therefor, a shaft journaled in the base and connected to the compressor, a casing, a. motor in the casing and connected to the shaft, means for maintaining the constant oil level inthe base, means for creating a partial vacuum in the base when the compressor is in operation, and a, connection between the lower ortion of the casin and V the base above t e level of the oil 1n the latter.

In testimony whereof I hereunto afiix mysignature.

GEORGE F.- WOELFEL. 

